Manufacturing method of coil component and coil component

ABSTRACT

A manufacturing method of a coil component comprising the steps of: preparing a coil assembly body in which a coil is attached on a magnetic core and a mold body which is formed with a cavity portion in the inside thereof and which includes at least one opening portion, putting a viscous admixture including magnetic powders and thermosetting resin and the coil assembly body in the cavity portion, pushing the put-in viscous admixture in the mold body, and thermally-curing the pushed-in viscous admixture and forming a magnetic exterior body which covers the coil assembly body.

CROSS REFERENCES TO RELATED APPLICATIONS

The present application is a continuation application of U.S. patentapplication Ser. No. 14/845,534, filed on Sep. 4, 2015, the entirecontents of which are incorporated herein by reference. The Ser. No.14/845,534 application claims priority under 35 U.S.C. § 119 to ChinesePatent Application CN201410462552.4 filed Sep. 11, 2014, the entirecontent of which is also incorporated herein by reference.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a manufacturing method of a coilcomponent and a coil component.

Description of the Related Art

There is known a coil component which is an electronic component havinga coil. There are various kinds of configurations for the coilcomponents and there are provided a lot of coil components in whichcoils are attached to magnetic cores and these coils are covered byexterior bodies.

For the material used for the exterior body, it is general to use anon-magnetic material such as an epoxy material or the like, but therehas been proposed also a coil component using a magnetic material inwhich magnetic bodies such as metal powders and the like are dispersedin a resin.

SUMMARY OF THE INVENTION

For a method of creating an exterior body by a magnetic material, it isconceivable to prepare such as a slurry-like or putty-like semi-fluidadmixture, which is formed by mixing metal powders and a resin and byadding a solvent, and to form an exterior body by filling that admixturein the periphery of the coil. On an occasion of mass-producing the coilcomponent provided with such an exterior body, it is required to employa technique in which filling leakage of the admixture does not occur atthe periphery or the like of the coil.

According to the present invention, there is provided a manufacturingmethod of a coil component comprising the steps of: preparing a coilassembly body in which a coil is attached on a magnetic core and a moldbody which is formed with a cavity portion in the inside thereof andwhich includes at least one opening portion, putting a viscous admixtureincluding magnetic powders and thermosetting resin and the coil assemblybody in the cavity portion, pushing the put-in viscous admixture in themold body, and thermally-curing the pushed-in viscous admixture andforming a magnetic exterior body which covers the coil assembly body.

In addition, in the manufacturing method of a coil component relating tothe present invention, for a more specific embodiment, it is allowedthat a press body is pressed against the viscous admixture in the stepof pushing.

In addition, in the manufacturing method of a coil component relating tothe present invention, for a more specific embodiment, it is allowedthat in the step of pushing, the press body is pressed against aswelling portion which is a part of the viscous admixture and whichoverflows from the opening portion for the planarization thereof.

In addition, in the manufacturing method of a coil component relating tothe present invention, for a more specific embodiment, it is allowedthat the swelling portion is rubbed and cut by separating the press bodywhich is pressed against the swelling portion from the viscous admixturewhile rotating it in the in-plane direction of the opening portion.

In addition, in the manufacturing method of a coil component relating tothe present invention, for a more specific embodiment, it is allowedthat the press body is pressed against the swelling portion whilerotating it in the in-plane direction of the opening portion.

In addition, in the manufacturing method of a coil component relating tothe present invention, for a more specific embodiment, it is allowedthat the viscous admixture put in the cavity portion is covered by a lidmember having excellent mold-releasable property, and in the step ofpushing, the viscous admixture is pushed-in by pressing the press bodyagainst the lid member.

In addition, in the manufacturing method of a coil component relating tothe present invention, for a more specific embodiment, it is allowedthat in the step of putting, the viscous admixture is put as far as alower position compared with the opening portion, there is provided thelid member having approximately the same shape as the opening portioninside the opening portion, and in the step of pushing, the press bodyhaving a thin diameter compared with the opening portion is pressedagainst the lid member.

In addition, in the manufacturing method of a coil component relating tothe present invention, for a more specific embodiment, it is allowedthat the viscous admixture which is pushed-in by being covered by thelid member is taken out from the mold body together with the coilassembly body, and the magnetic exterior body is formed bythermally-curing the taken-out viscous admixture.

In addition, in the manufacturing method of a coil component relating tothe present invention, for a more specific embodiment, it is allowedthat in the step of forming, the viscous admixture is thermally-curedinside the mold body and the magnetic exterior body is formed.

In addition, in the manufacturing method of a coil component relating tothe present invention, for a more specific embodiment, it is allowedthat the viscous admixture is thermally-cured inside the mold body by afirst temperature, the semi-cured viscous admixture is taken out fromthe mold body together with the coil assembly body, and the taken-outviscous admixture is thermally-cured by a second temperature which is ahigher temperature than the first temperature.

In addition, in the manufacturing method of a coil component relating tothe present invention, for a more specific embodiment, it is allowedthat the mold body is formed by a resin material having an excellentmold-releasable property.

In addition, in the manufacturing method of a coil component relating tothe present invention, for a more specific embodiment, it is allowedthat the mold body has flexibility and also includes the alignedplurality of cavity portions, in the step of putting, the viscousadmixtures and the coil assembly bodies are put in the plurality ofcavity portions respectively, in the step of forming, the viscousadmixtures are thermally-cured inside the mold body respectively and theplurality of magnetic exterior bodies are formed, and the formedplurality of magnetic exterior bodies are taken out from the cavityportions by bending the mold body such that the mold body is bentbackward toward the alignment direction of the cavity portions.

In addition, in the manufacturing method of a coil component relating tothe present invention, for a more specific embodiment, it is allowedthat the mold body includes a plurality of split-molds which define thecavity portions by being mutually combined.

In addition, in the manufacturing method of a coil component relating tothe present invention, for a more specific embodiment, it is allowedthat the split-molds are removed from the viscous admixture which waspushed-in the step of pushing by mutually separating the plurality ofsplit-molds and the magnetic exterior body is formed by thermally-curingthe viscous admixture from which the split-molds were removed.

In addition, in the manufacturing method of a coil component relating tothe present invention, for a more specific embodiment, it is allowedthat in the step of putting, the coil assembly body is attached to thebottom portion of the cavity portion and thereafter, the coil assemblybody is buried by putting the viscous admixture, and in the step ofpushing, the viscous admixture facing the opening portion is pressedtoward the coil assembly body.

In addition, in the manufacturing method of a coil component relating tothe present invention, for a more specific embodiment, it is allowedthat the coil assembly body includes a terminal portion which isconnected to the coil and which is exposed from the magnetic core, andat the bottom portion of the cavity portion, there is provided a concaveportion which houses the terminal portion and which separates theterminal portion and the viscous admixture.

In addition, in the manufacturing method of a coil component relating tothe present invention, for a more specific embodiment, it is allowedthat the coil assembly body includes a terminal portion which isconnected to the coil and which is exposed from the magnetic core, inthe step of putting, the viscous admixture is put in the cavity portionand thereafter, the coil assembly body is placed on the viscousadmixture such that the terminal portion is exposed from the viscousadmixture, and in the step of pushing, the placed coil assembly body ispressed toward the viscous admixture in the pushing-in direction.

In addition, in the manufacturing method of a coil component relating tothe present invention, for a more specific embodiment, it is allowedthat a thermosetting-resin coated-layer is formed on the surface of theformed magnetic exterior body.

According to the present invention, there is provided a coil componentmanufactured by the aforesaid manufacturing method of a coil component.

In addition, according to the present invention, there is provided acoil component comprising: a coil assembly body in which a coil isattached to a magnetic core; a magnetic exterior body which includesmagnetic powders and thermosetting resin and concurrently which coversthe coil assembly body; and a terminal portion which is connected to thecoil and which is exposed from the magnetic exterior body, wherein onthe counter surface of the terminal portion within the magnetic exteriorbody, there are formed a plurality of scratch marks havingconcentric-circle shapes.

In addition, according to the present invention, there is provided acoil component comprising: a coil assembly body in which a coil isattached to a magnetic core; a magnetic exterior body which includesmagnetic powders and thermosetting resin and concurrently which coversthe coil assembly body; and a terminal portion which is connected to thecoil and which is exposed from the magnetic exterior body, wherein onthe counter surface of the terminal portion within the magnetic exteriorbody, there are arranged magnetic powders smoothly compared with thecircumferential surfaces adjacent to the counter surface.

According to the manufacturing method of the coil component relating tothe present invention, the viscous admixture which is put in the cavityportion is pushed therein and therefore, the viscous admixture is filledin the periphery or the like of the coil assembly body without causingan air gap. The viscous admixture includes the thermosetting resin andtherefore, it is possible to create a magnetic exterior body withoutfilling leakage by thermally-curing the viscous admixture which ispushed therein. In addition, the coil component relating to the presentinvention is a component which is created by the aforesaid manufacturingmethod or a component which suggests that it was created by theaforesaid manufacturing method, in which it is possible to form themagnetic exterior body without causing an air gap, and the coilcomponent is a coil component excellent in the productivity.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective view showing one example of a coil componentrelating to an exemplified embodiment of the present invention;

FIG. 1B is a cross-sectional view at Line B-B in FIG. 1A;

FIG. 2A, FIG. 2B and FIG. 2C are front elevational views schematicallyshowing first to fourth manufacturing methods of the coil component;

FIG. 3 is an exploded perspective view of showing a mold body which isused in the first to fourth manufacturing methods;

FIG. 4A is a plan view schematically showing a pushing-in process in thefirst to fourth manufacturing methods;

FIG. 4B is a plan view schematically showing a modified example of thepushing-in process in the first to fourth manufacturing methods;

FIG. 5A is an exploded perspective view showing a mold body which isused in fifth and sixth manufacturing methods of the coil component;

FIG. 5B is an exploded perspective view showing a modified example ofthe mold body which is used in the fifth and sixth manufacturingmethods;

FIG. 6A, FIG. 6B and FIG. 6C are front elevational views schematicallyshowing seventh and eighth manufacturing methods of the coil component;

FIG. 7A, FIG. 7B and FIG. 7C are front elevational views schematicallyshowing a ninth manufacturing method of the coil component;

FIG. 8A, FIG. 8B and FIG. 8C are front elevational views schematicallyshowing a tenth manufacturing method of the coil component;

FIG. 9A is a photograph showing a planar view state after the pushing-inprocess in the first manufacturing method;

FIG. 9B is a photograph showing a planar view state after the pushing-inprocess in the manufacturing method relating to a reference-example 1;

FIG. 9C is a photograph showing a planar view state after the pushing-inprocess in the manufacturing method relating to a reference-example 2;

FIG. 10 is a flowchart showing a whole process in the manufacturingmethod of the coil component relating to the present invention;

FIG. 11 is a flowchart showing a preparing process in the first to tenthmanufacturing methods;

FIG. 12 is a flowchart showing a putting-in process in the first totenth manufacturing methods;

FIG. 13 is a flowchart showing a pushing-in process in the first totenth manufacturing methods; and

FIG. 14 is a flowchart showing a forming process in the first to tenthmanufacturing methods.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, exemplified embodiments of the present invention will beexplained based on the drawings. It should be noted that commonreference numerals are applied to the corresponding constituent elementsin the respective drawings and repetitive explanations will be omittedappropriately.

Hereinafter, a manufacturing method of a coil component relating to thepresent invention will be explained by using a plurality of processeswhich will be described in order, in which the order of the descriptionsthereof is not to limit the order or the timing for executing theplurality of processes. When implementing the manufacturing method ofthe present invention, it is possible to change the order of theplurality of processes thereof within a range not causing a trouble interms of the contents thereof and in addition, it is allowed for aportion of or the whole of the timing for executing the plurality ofprocesses to be overlapped one another. For example, it is allowed toexecute the putting-in process and the pushing-in process mentionedbelow at a timing overlapping each other and it is also allowed toexecute the pushing-in process and the forming process at a timingoverlapping each other.

It should be noted that on an occasion when explaining the coilcomponent and the manufacturing method thereof, there is a case in which“upward” or “downward” is named in conformity with the direction of theindication of each drawing, but this naming is for a descriptive purposeof appropriately explaining the relative positional relations of therespective elements, in which “downward” does not always mean“vertically downward direction”. For example, in the followingexplanation, there is exemplified an embodiment of putting a viscousadmixture in the downward direction with respect to a cavity portion ofa mold body, but it is not always necessary for the putting-in directionof the viscous admixture to be in conformity with the downward directionin the vertical direction. It is allowed to put the viscous admixture inthe direction crossing with respect to the vertically downward directionor it is also allowed to inject the viscous admixture into the cavityportion of the mold body toward the direction upward compared with thehorizontal direction. With regard to any of these cases, there will beused an expression that the viscous admixture is put in the cavityportion of the mold body.

<Coil Component>

FIG. 1A is a perspective view showing one example of a coil component100 relating to an exemplified embodiment of the present invention. FIG.1B is a cross-sectional view at Line B-B in FIG. 1A. In FIG. 1A, fordescriptive purposes, a magnetic exterior body 20 is illustrated bybroken lines and a coil assembly body 10 which is covered by themagnetic exterior body 20 is illustrated by solid lines. In FIG. 1B,hatching is applied only to the cross-section surface of the magneticexterior body 20 and hatching is omitted for the cross-sectional surfaceof the coil assembly body 10.

First, there will be explained an outline of the coil component 100 ofthis exemplified embodiment. The coil component 100 of this exemplifiedembodiment is an electronic component which includes a coil 15 and inwhich the coil 15 generates inductance by supplying power to a terminalportion 16, and specifically, this component is an inductor, atransformer, a choke coil or the like. In this exemplified embodiment,for the sake of simplicity, an inductor having a single winding isillustrated by an example as the coil component 100.

The coil component 100 is provided with the coil assembly body 10 inwhich the coil 15 is attached to a magnetic core 12, the magneticexterior body 20 which includes magnetic powders and thermosetting resinand concurrently which covers the coil assembly body 10, and theterminal portion 16 which is connected to the coil 15 and which isexposed from the magnetic exterior body 20.

The magnetic core 12 is provided with a plate-shaped portion 13 and acore portion 14 which rises from this plate-shaped portion 13. In thisexemplified embodiment, there is exemplified an aspect in which theplate-shaped portion 13 forms a rectangular plate shape and the coreportion 14 forms a cylindrical shape, but the present invention is notlimited by this aspect. In addition, in this exemplified embodiment,there is exemplified an aspect in which a plate-shaped portion 13 isformed only on a single end side (lower end side in FIG. 1B) of the coreportion 14, but the present invention is not limited by this aspect andit is allowed for the plate-shaped portion 13 to be formed on the bothend sides of the core portion 14.

The plate-shaped portion 13 and the core portion 14 are formed by asingle material integrally and constitute the magnetic core 12. Themagnetic core 12 is a ferrite core formed by burning ferrite or a dustcore formed by compressing and molding magnetic powders. For themagnetic powders of the dust core, it is possible to use magneticpowders in which iron (Fe) is made to be the main component and in whichsilicone (Si) and chromium (Cr) are added respectively in a ratio of 1wt % or more and also of 10 wt % or less. Such magnetic powders areexcellent in terms of rust resistance, relative permeability or thelike. From the viewpoint of reducing core loss, it is also allowed touse metal magnetic powders formed by mixing the aforesaid magneticpowders and amorphous metals. For the amorphous metal, it is possible touse a carbon containing amorphous metal in which iron (Fe) is made to bethe main component and in which silicone (Si) and chromium (Cr) arecontained respectively in a ratio of 1 wt % or more and also of 10 wt %or less, and further, in which carbon (C) is contained in a ratio of 0.1wt % or more and also of 5 wt % or less.

The coil 15 is constituted by applying single winding or multiplewindings for the winding. It is also allowed for the winding to use notonly a round wire but also a flat wire. In this exemplified embodiment,there is used a rectangular wire whose width size is adequately largecompared with the thickness size thereof. The coil 15 of thisexemplified embodiment is a so-called edgewise coil which is woundspirally by setting short sides of the rectangular wire in a thediameter direction and by setting the thickness-direction (up and downdirection in FIG. 1B) of the rectangular wire parallel to thewinding-axis direction of the coil. In this exemplified embodiment,there is illustrated as an example a coil 15 obtained by winding-aroundthe wire beyond five turns and in which the windings are mutuallylaminated, but the number of turns is not limited by this aspect.

A wound portion 18 of the coil 15 is attached to the periphery of thecore portion 14 such that the extending direction of the core portion 14will coincide with the winding-axis direction. It is allowed for thelower surface of the wound portion 18 of the coil 15 to be adhesivelyfixed by using an adhesive agent with respect to the upper surface ofthe plate-shaped portion 13 of the magnetic core 12. It is possible forthe adhesive agent to use a resin adhesive agent having an insulatingcharacteristic.

A non-wound portion 19 drawn from the wound portion 18 within the coil15 is bent toward the downward direction along the side surface of theplate-shaped portion 13 of the magnetic core 12 and further is bentagain so as to go along the lower surface of the plate-shaped portion13, in which there is constituted a terminal portion 16. Further, eachdistal end of the non-wound portion 19 within the coil 15 is bent so asto rise upward from the plate-shaped portion 13, in which there isconstituted a terminal-end portion 17. Toward the core portion 14 theterminal-end portion 17 is bent slightly to the inside of the magneticexterior body 20. Thus, the terminal-end portions 17 are prevented fromprotruding from the magnetic exterior body 20. On the side surface ofthe plate-shaped portion 13 of the magnetic core 12, there are formedside-surface concave portions having groove-shapes (not shown) for beingfitted with the non-wound portion 19 (including terminal-end portion 17)of the coil 15. Thus, a portion of or the whole of the thickness of thewinding (rectangular wire) of the non-wound portion 19 is housed in theside-surface concave portion and therefore, it is possible to reduce thethickness by which the non-wound portion 19 protrudes from the sidesurface of the plate-shaped portion 13. It is allowed for the non-woundportion 19 of the coil 15 to be adhesively fixed onto the side-surfaceconcave portion of the plate-shaped portion 13 by using an adhesiveagent.

In addition, on the bottom surface of the plate-shaped portion 13, thereis formed an electrode groove having a groove-shape (not shown) forbeing fitted with the terminal portion 16 of the non-wound portion 19.The width of the electrode groove is approximately the same as that ofthe terminal portion 16. The depth of the electrode groove is shallowcompared with the thickness of the winding (rectangular wire) of thenon-wound portion 19 and the electrode groove houses a portion of thethickness of the terminal portion 16. Thus, the terminal portion 16 willbe fitted with the electrode groove in a state in which the lowersurface of the terminal portion 16 protrudes downward compared with thebottom surface of the plate-shaped portion 13. It is allowed for theupper surface of the terminal portion 16 to be adhesively fixed on tothe electrode groove of the plate-shaped portion 13 by using an adhesiveagent.

The terminal portion 16 is a portion of the coil 15 and is connectedwith the wound portion 18 of the coil 15. The terminal portion 16 isexposed from the magnetic exterior body 20 and is used as an electrode.The terminal portion 16 is formed flatly along the lower surface of thecoil component 100 and is used as a surface-mounting terminal. The coil15 is applied with insulation coating except the lower surface side ofthe terminal portion 16.

In addition to the above, it is allowed for the coil 15 to employ aconfiguration in which the wound portion 18 is formed by using a roundwire and the terminal portion 16 is created by flatly crushing thelongitudinal area for the portion portioned at the lower surface of theplate-shaped portion 13.

The magnetic exterior body 20 is composed of a material containingmagnetic powders and thermosetting resin and covers the coil assemblybody 10. The wording “the magnetic exterior body 20 covers the coilassembly body 10” means that the magnetic exterior body 20 covers atleast a portion of the coil assembly body 10. The magnetic exterior body20 of this exemplified embodiment forms an approximately rectangularshape and embeds the whole of the wound portion 18 of the coil 15 andthe core portion 14 of the magnetic core 12. However, the shape of thebody 20 can be designed arbitrary and is not to be limited by“approximately rectangular shape”.

The terminal portion 16 is exposed from the lower surface side of themagnetic exterior body 20. It is allowed for the plate-shaped portion 13of the magnetic core 12 to be covered totally by the magnetic exteriorbody 20 or it is also allowed to employ a configuration in which aportion of the lower surface or the like of the plate-shaped portion 13is exposed from the magnetic exterior body 20. In this exemplifiedembodiment, there is illustrated as an example a configuration in whichthe lower surface of the plate-shaped portion 13 and terminal portion 16are exposed from the magnetic exterior body 20, and the magneticexterior body 20 embeds and covers the circumferential surface and theupper surface, from which the core portion 14 protrudes, of theplate-shaped portion 13, and the coil assembly body 10 except theterminal portion 16.

It is allowed for the magnetic powders constituting the magneticexterior body 20 to use the same kind of material as that of themagnetic core 12 or it is also allowed to use a different material.

Such a coil component 100 of this exemplified embodiment is manufacturedby one of the first to tenth manufacturing methods (referred to as fromfirst manufacturing method to tenth manufacturing method, respectively)which will be explained hereinafter. There is a case in which the firstto tenth manufacturing methods are named as “this method” all together.

FIG. 10 is a flowchart showing a whole process in the manufacturingmethod of the coil component 100 and this flowchart is common for thefirst to tenth manufacturing methods. First, there will be explained theoutline of this method.

This method includes a preparing process S10, a putting-in process S20,a pushing-in process S30 and a forming process S40. The preparingprocess S10 is a process for preparing a coil assembly body 10 in whicha coil 15 is attached to a magnetic core 12, and a mold body 60 in whicha cavity portion 62 is formed thereof and which includes at least oneopening portion 70. The putting-in process S20 is a process for puttinga viscous admixture 50, which includes magnetic powders andthermosetting resin, and a coil assembly body 10 in the cavity portion62. The pushing-in process S30 is a process for pushing the put-inviscous admixture 50 in the mold body 60. Then, the forming process S40is a process for thermally-curing the pushed-in viscous admixture 50 andfor forming a magnetic exterior body 20 which covers the coil assemblybody 10.

It should be noted that the wording “pushing-in process” in this methodmeans that the viscous admixture 50, which is the processing target, isdeformed substantially without changing the volume thereof; is moved asfar as every corner of the cavity portion 62 of the mold body 60; and isfully filled therein. Therefore, the “pushing-in process” in this methodis distinguished from a conventional “compression process” in which thevolume is significantly reduced by compressing the processing targetsuch as ferrite by using a high pressure. While a high pressing forcefrom around 0.5 tons to several tons is generally loaded onto theprocessing target in the conventional “compression process”, it issufficient for the “pushing-in process” in this method if a low pressingforce such as, for example, from around 0.5 kg to 50 kg is to be loadedonto the viscous admixture 50. For this reason, the “pushing-in process”in this method has such a merit that damage to the mold body 60 islittle and therefore, the selection range of the material for the moldbody 60 becomes wide.

Next, there will be explained this method in detail.

FIG. 11 is a flowchart showing a preparing process S10 in the first totenth manufacturing methods. FIG. 12 is a flowchart showing a putting-inprocess S20 in the first to tenth manufacturing methods. FIG. 13 is aflowchart showing a pushing-in process S30 in the first to tenthmanufacturing methods. FIG. 14 is a flowchart showing a forming processS40 in the first to tenth manufacturing methods. In the flowcharts ofFIG. 11 to FIG. 14, suffix “a” is applied for the process correspondingto the first manufacturing method. Similarly, suffixes from “b” to “j”are applied sequentially to the processes corresponding to the methodsfrom the second manufacturing method to the tenth manufacturing method.

In the preparing process S10, there are prepared the mold body 60, thecoil assembly body 10 and the viscous admixture 50. It is possible forthe processes from S11 a to S11 j and the processes S12 and S13 shown inFIG. 11 to be carried out in arbitrary orders, it is not alwaysnecessary to be carried out in the order shown in FIG. 11 and it isallowed for the portions of the implementation timings to be overlappedone another.

In the methods from the first manufacturing method to the tenthmanufacturing method, a plurality of different mold bodies 60 are used.Therefore, the processes S11 a to S11 j which prepare mold bodies 60will be mentioned individually in the explanations of the respectivemanufacturing methods mentioned below.

In the process S12 for preparing the coil assembly body 10, a woundportion 18 of a coil 15 is formed by winding a rectangular wire into anEdgewise shape. Such a coil 15 is attached onto a magnetic core 12 whichincludes a core portion 14 and a plate-shaped portion 13, and isadhesively fixed one another by an adhesive agent arbitrarily. Inaddition, the non-wound portion 19 of the coil 15 is bend along theplate-shaped portion 13 and the terminal portion 16 and the terminal-endportion 17 are formed, and further, the insulating coating of theportion 16 is removed. Thus, the coil assembly body 10 is created.

In the process S13 for preparing the viscous admixture 50, the viscousadmixture 50 is prepared by kneading the magnetic powders and thethermosetting resin. For the magnetic powder which is the firstcomponent in the viscous admixture 50, it is possible to use a metalmagnetic powder including iron as the main component, in which there isadded chromium (Cr), silicone (Si), manganese (Mn) or the like. Inaddition to this aspect, it is allowed for the metal magnetic powder tobe added with nonmetal-material powder such as of carbon or the like. Itis possible for the thermosetting resin which is the second component inthe viscous admixture 50 to list up epoxy resin, phenol resin andsilicone resin as examples.

Other than the aforesaid components, it is possible to add a solventselectively to the viscous admixture 50. More specifically, for thethird component of the viscous admixture 50, it is possible to include asolvent. Thus, it is possible to set the viscous admixture 50 to have adesired coefficient viscosity. In other words, in case of not adding asolvent to the viscous admixture 50, the viscous admixture 50 will havea high coefficient viscosity and the fluidity thereof becomes very low.In addition, in case of not adding a solvent to the viscous admixture50, the process for removing the solvent becomes unnecessary in whichthere is an effect of reducing the number of processes in this method.On the one hand, in case of adding a solvent to the viscous admixture50, the coefficient viscosity of the viscous admixture 50 becomes low.For this reason, in case of filling this viscous admixture 50 in themold body 60, it is possible to fully fill the viscous admixture 50 inthe cavity portion 62 of the mold body 60 without gaps. In addition, incase of adding a solvent in the viscous admixture 50, it is necessary tocarry out a process for removing the solvent. It is possible to carryout the process for removing the solvent between the pushing-in processS30 and the forming process S40 or during the forming process S40.

It is possible for the solvent to use a liquid in which amphiphilicmolecules including both of hydrophilic group and lipophilic group aremade to be main components, and specifically, it is possible to use analcohol such as terpineol (terpineol) or a volatile organic solvent suchas acetone.

For a specific viscous admixture 50, it is possible to mix the metalmagnetic powders and the epoxy resin by the mass ratio of 91:9 to 95:5(both the ends values are inclusive) with regard to the component ratiothereof. Further, it is possible to prepare the composite by adding asolvent selectively. For one example of the metal magnetic powder, it ispossible to cite a powder obtained by mixing an amorphous metal magneticpowder, which at least contains iron, silicone, chromium and carbon, andan iron-silicone-chromium based alloy powder by a mass ratio of 1:1.

A solvent is not added to the viscous admixture 50, or even in a case inwhich a solvent is added, it is possible by using terpineol as thesolvent to set the addition amount of the solvent to be less than 2 wt %with respect to the mass of the viscous admixture 50. Thus, it ispossible to set the viscous admixture 50 in a putty-like state in whichthe fluidity is low. Such a viscous admixture 50 has a high coefficientviscosity so as not to flow or disperse like a liquid even in a case ofbeing placed on a plane surface. Instead of the above, in case of addinga solvent to the viscous admixture 50, it is possible, by using acetonefor this solvent and also by setting the addition amount of the solventto be 2 wt % or more, to set the viscous admixture 50 in a slurry statein which the fluidity is comparatively high.

Hereinafter, there will be sequentially explained the features which areinherent in the methods from the first manufacturing method to the tenthmanufacturing method.

<First Manufacturing Method>

FIG. 2A, FIG. 2B and FIG. 2C are front elevational views schematicallyshowing first to fourth manufacturing methods of the coil component 100.It should be noted in FIGS. 2A to 2C that with regard to the hatchingshowing the cross-section of the coil assembly body 10, the illustrationthereof is omitted. FIG. 3 is an exploded perspective view of showing amold body 60 which is used in the first to fourth manufacturing methods.FIG. 4A is a plan view schematically showing a pushing-in process S30 inthe first to fourth manufacturing methods. FIG. 4B is a plan viewschematically showing a modified example of the pushing-in process inthe first to fourth manufacturing methods.

In the processes S11 a to S11 d within the preparing process S10, thereare prepared an integrated jig 61 and a bottom unit 64 for the mold body60. The integrated jig 61 is a frame body for which a plurality ofcavity portions 62 are formed therethrough. It is possible to create theintegrated jig 61 by a metal material such as stainless steel or thelike, but it is allowed to create it by a resin material having anexcellent mold-releasable property, which is exemplified by afluororesin material such as polytetrafluoroethylene (PTFE) or the like.

In FIG. 3, an integrated jig 61 formed with 6 pieces of cavity portions62 is shown as an example, but the number of the cavity portions 62 arenot limited in particular and it is allowed to provide, for example, 10pieces or the like. In FIG. 3, an integrated jig 61 for which aplurality of cavity portions 62 are aligned in line is shown as anexample, but it is not limited by this configuration. It is also allowedfor the cavity portions 62 to be aligned in a plurality of columns suchas in a lattice-shape, in a zigzag-like shape or the like.

The bottom unit 64 is a member which is attached to the downward side ofthe integrated jig 61 and closes the openings on the downward side ofthe cavity portions 62. By combining the integrated jig 61 and thebottom unit 64, there is constituted the mold body 60 in which theopening portions 70 open toward the upward direction of the cavityportions 62 respectively. The integrated jig 61 and the bottom unit 64are integrally assembled by a holder (not shown).

It is preferable to coat a release-agent on the circumferential wallsurface of the cavity portion 62. Thus, in a process S42 a of theforming process S40, which will be mentioned later, it is possible totake out the coil components 100 from the mold body 60 easily.

As described above, the coil assembly body 10 is connected to the coil15 and includes the terminal portions 16 which are exposed from themagnetic core 12. At the bottom unit 64 of the cavity portion 62, thereare provided concave portions 66 which house the terminal portions 16and separate the terminal portions 16 and the viscous admixture 50. Theconcave portions 66 are formed at the positions corresponding to thepair of the terminal portions 16. For the bottom unit 64, there areformed a plurality of pairs of concave portions 66 at the positionscorresponding to the plurality of the cavity portions 62 respectively.It is allowed for the concave portions 66 to be penetrating grooves(slits) which penetrate the bottom unit 64 or it is also allowed toemploy bottomed concave grooves.

Between the pair of the concave portions 66, there is formed a vent 65which penetrates the bottom unit 64. The vent 65 is formed with respectto each pair of the plurality of pairs of the concave portions 66. Thus,in a state in which the coil assembly body 10 is put in the cavityportion 62 and the terminal portions 16 are fitted with the concaveportion 66 of the bottom unit 64, it is possible to discharge the airinside the cavity portion 62 from the vent 65.

In the putting-in process S20 for the first to fourth manufacturingmethods, as shown in FIG. 12, the coil assembly body 10 is put in thecavity portion 62 (Processes S21 a to S21 d) and thereafter, the viscousadmixture 50 is put in the cavity portion 62 (Processes S22 a to S22 d).

More specifically, in the putting-in process S20 of the firstmanufacturing method, the coil assembly body 10 is attached onto thebottom unit 64 of the cavity portion 62 and thereafter, the viscousadmixture 50 is put-in and the coil assembly body 10 is buried. Then, inthe pushing-in process S30, the viscous admixture 50 which faces theopening portion 70 is pressed toward the coil assembly body 10.

In more specifically, the viscous admixtures 50 are measured beforehandand are put in the cavity portions 62 respectively. In a case in whichthe viscous admixture 50 is in a slurry state, the viscous admixture 50is filled in the periphery of the coil assembly body 10 by thatadmixture and the cavity portion 62 is filled with the viscous admixture50. In addition, in a case in which the viscous admixture 50 is in aputty-like state, a lot of the viscous admixture 50 remains in a stateof being contact with the upper portion of the coil assembly body 10 andonly a portion of the cavity portion 62 is fully filled with the viscousadmixture 50. Further, in the first manufacturing method, as shown inFIG. 2A, a viscous admixture 50 having a volume more than the volumethat is obtained by excluding the coil assembly body 10 from theinternal volume of the cavity portion 62 is put in the cavity portion 62in a state of rising from the level of the opening portion 70 of themold body 60. Thus, as shown in FIG. 2A, for the viscous admixture 50,there is formed a swelling portion 52 which overflows from the openingportion 70.

In the pushing-in process S30 of the first manufacturing method shown inFIG. 2A and FIG. 13, the planarization is realized by pressing the pressbody 30 against the swelling portion 52 which overflows from the openingportion 70 within the viscous admixture 50. Thus, the viscous admixture50 which is in a state of rising from the opening portion 70 isflattened and concurrently, at least a portion of the viscous admixture50 is pushed in the cavity portion 62 and the viscous admixture 50 isfilled in the whole cavity portion 62.

The press body 30 is a jig having a rod-shape which is providedelevatably with respect to the mold body 60. There is formed a graspingportion 32 having a rectangular cross-section at the upper portion ofthe press body 30. The grasping portion 32 is a head portion for beingfixed to a chucking device (not shown). The chucking device iselevation-driven with respect to the mold body 60 by an elevationmechanism of a hydraulic control system (not shown). There is nolimitation for the shape of the grasping portion 32 in particular and itis possible to employ a prismatic shape such as of a rectangular body,of a hexagonal column or the like. Thus, it is possible to fix thegrasping portion 32 to the chucking device firmly.

By pressing the press body 30 against the viscous admixture 50 in thepushing-in process S30, the swelling portion 52 is pressed physicallyand the viscous admixture 50 is impregnated in the whole inside thecavity portion 62 such as the gaps of the coil 15 or the like. At thattime, the air which existed inside the cavity portion 62 is dischargedfrom the vent 65 of the bottom unit 64 toward the downward direction ofthe mold body 60.

In the pushing-in process S30 of the first manufacturing method, thepress body 30 descends with respect to the mold body 60 withnon-rotation substantially without rotation (Process S31 a). Thus, astatic pressure is applied with respect to the swelling portion 52 ofthe viscous admixture 50. It should be noted that the rotation of thepress body 30 is shown by broken lined arrows in FIG. 2A and this meansthat in a second and a fourth manufacturing methods mentioned below, thepress body 30 is descended toward the mold body 60 while being rotated.

Next, in the pushing-in process S30 of the first manufacturing method,as shown in FIG. 2B, the press body 30 which is pressed against theswelling portion 52 is separated from the viscous admixture 50 whilebeing rotated toward the in-plane direction of the opening portion 70.Thus, it is possible to rub and cut the swelling portion 52 of theviscous admixture 50 by the rotating press body 30 (Process S32 a inFIG. 13).

Here, the matter that the press body 30 is separated from the viscousadmixture 50 by being ascended while being rotated includes both of anaspect in which the press body 30 is ascended at the same time with therotation start and an aspect in which the press body 30 is ascendedafter being rotated in contact with the lid member 40 in a predeterminedtime period. It should be noted that the processes S32 a to S32 d inwhich the press body 30 is ascended from the mold body 60 while beingrotated are common in the first to fourth manufacturing methods.

In the planar view of the mold body 60 (see FIG. 4A), a passing areawhen the press body 30 is axially-rotated covers the whole of theopening portion 70 of the mold body 60. Thus, by axially-rotating thepress body 30 at the height position at which the lower surface of thepress body 30 is in contact with the opening portion 70 of the mold body60, the swelling portion 52 of the viscous admixture 50 is cut off andscattered toward the outward direction of the opening portion 70 (seeFIG. 2B). For this reason, the viscous admixture 50 is rubbed and cut bythe axial-rotation action of the press body 30. It should be noted inFIG. 4A that with regard to the grasping portion 32 (see FIG. 2A) whichis integrally formed on the upward side of the press body 30, thegraphic illustration thereof is omitted.

For one example of the press body 30, it is possible to cite arod-shaped body (pin) having a cylindrical shape as shown in FIG. 4A.The diameter of the circular cross-section obtained by cutting the pressbody 30 perpendicularly with respect to the rotation axis is larger thanthe diagonal length of the opening portion 70. The rotation axis of thepress body 30 is approximately in conformity with the center axis of theopening portion 70 in the planar view thereof. Thus, the press bodies 30rotate axially around the center axes of the opening portions 70, applyshearing stresses simultaneously with respect to the whole swellingportions 52 (see FIG. 2A) which overflow from the opening portions 70,and rub and cut these swelling portions.

In case of using a cylindrical press body 30, the diameter of the pressbody 30 is larger than the diagonal length of the opening portion 70 asdescribed above and also is smaller than the distance between thecenters of the opening portions 70 adjacent to each other. Thus, asshown in FIG. 4A, when the press bodies 30 which are disposed for therespective opening portions 70 are axially-rotated, the press bodies 30adjacent to each other will never interfere with each other. Inaddition, as shown in FIG. 2A, owing to the fact that the graspingportion 32 has a small diameter compared with that of the press body 30,it is possible to prevent the chucking devices which grasp the graspingportions 32 adjacent to each other from interfering with each other.

With regard to the press body 30 shown in FIG. 4A, the diameter (longdiameter) thereof is larger than the diagonal length of the openingportion 70 and the axially-rotating press body 30 covers the openingportion 70 completely in the planar view of the mold body 60. However,so long as it is possible for the press body 30 to cover the whole ofthe opening portion 70 by one rotation or more rotations, it is notnecessary in the planar view to always cover the whole of the openingportion 70.

The press body 30 shown in FIG. 4B as a modified example is constitutedsuch that by setting the long diameter thereof to be shorter than thediagonal length of the opening portion 70 and by axially-rotating thegrasping portion 32, the passing area of the press body 30 will coverthe whole opening portion 70. The press body 30 of this modified exampleforms a cross-section having an elliptical shape and the long diameterthereof is longer than the half of the diagonal length of the openingportion 70 and also is shorter than the diagonal length of the openingportion 70. The center of the grasping portion 32 is approximately inconformity with the center of the opening portion 70. Byaxially-rotating the grasping portion 32, the press body 30 covers thewhole opening portion 70 during one rotation and it is possible to ruband cut the swelling portion 52 of the viscous admixture 50. So long asthe press bodies 30 which are provided respectively at the adjacentplurality of opening portions 70 do not interfere one another, it isallowed to axially-rotate the adjacent press bodies 30 toward the samedirections or toward the opposite directions. In FIG. 4B, there isillustrated an aspect as an example in which the adjacent press bodies30 protrude respectively toward the same directions from the graspingportions 32 and also axially-rotate toward the same directions.

It should be noted for still another modified example of the press body30 that it is allowed, by using a planetary gear mechanism or the likeand by axially-rotating the grasping portion 32 while being made to beeccentric, to enlarge the passing area of the press body 30. In thiscase, it is possible to shorten the long diameter of the press body 30than the diagonal length of the opening portion 70. In other words, itis enough if the total length of the eccentric length (radius) of thegrasping portion 32 and the long diameter of the press body 30 exceedsthe half of the diagonal length of the opening portion 70. Thus, it ispossible to cover the whole opening portion 70 owing to the fact thatthe press body 30 rotates a plurality of times.

FIG. 9A is a photograph showing a planar view state after the pushing-inprocess (S30) in the first manufacturing method. As shown in the samedrawing, it is possible to confirm that the viscous admixture 50 isrubbed and cut by the same surface as the upper surface of the mold body60 and the viscous admixture 50 is filled in the whole opening portion70 without a gap.

FIG. 9B is a photograph showing a planar view state after the pushing-inprocess in the manufacturing method relating to a reference-example 1.The manufacturing method of the reference-example 1 is a method in whichinstead of the process S32 a of the first manufacturing method, thepress body 30 is separated vertically from the mold body 60 withoutrotation (see FIG. 2B). According to such a manufacturing method, it ispossible to fill the viscous admixture 50 tightly in the periphery ofthe coil assembly body 10 by pushing the viscous admixture 50 in themold body 60 by using the press body 30. However, the press body 30 isremoved in a state that a portion of the viscous admixture 50 facing theopening portion 70 adheres to the lower surface thereof and therefore,concave or convex portions 71 are caused on the surface of the magneticexterior body 20 and the surface is in a rough condition.

FIG. 9C is a photograph showing a planar view state after the pushing-inprocess in the manufacturing method relating to a reference-example 2.The manufacturing method of the reference-example 2 is a method in whichinstead of the process S32 a of the first manufacturing method, thepress body 30 is slid toward the horizontal direction along the openingportion 70 without rotation (see FIG. 2B). Specifically, the press body30 is slid toward the left direction in FIG. 9C. According to such amanufacturing method, it is possible to fill the viscous admixture 50tightly in the periphery of the coil assembly body 10 by pushing theviscous admixture 50 in the mold body 60 by using the press body 30.However, the putty-like viscous admixture 50 having high viscosityadheres to the lower surface of the press body 30 and is dragged towardthe horizontal direction and therefore, defective portions 72 of theviscous admixture 50 are caused at a portion of the area on the leftside of the opening portion 70.

More specifically, according to the first manufacturing method shown inFIG. 9A, it is possible, by carrying out the process S32 a in which forrubbing and cutting the viscous admixture 50 by rotating the press body30 and even if using the putty-like viscous admixture 50 having highviscosity, to fill this admixture in the whole cavity portion 62 andalso to complete the surface of the viscous admixture 50 facing theopening portion 70 in a flat condition.

The coil component 100 which is manufactured by the first manufacturingmethod has a feature in which a plurality of concentric scratch marks 23are formed on a counter surface 22 with respect to the terminal portions16 within the magnetic exterior body 20 (see FIG. 2C and FIG. 9A). Thescratch marks 23 are caused by a phenomenon in which the magneticpowders included in the viscous admixture 50 are dragged in concentricshapes by the friction with respect to the lower surface of the pressbody 30. More specifically, the fact that a plurality of concentricscratch marks 23 are formed on the counter surface 22 of the terminalportions 16 within the magnetic exterior body 20 expresses a matter thatthe viscous admixture 50 is rubbed and cut by the rotating press body 30in a state of being pushed in the mold body 60. For such a coilcomponent 100, the magnetic exterior body 20 is filled in the peripheryof the coil assembly body 10 without a gap, so that the component isexcellent in the thermal and mechanical characteristics and is excellentin the yield property. In other words, the coil component 100 havingsuch a scratch mark 23 on the counter surface 22 with respect to theterminal portions 16 is excellent in productivity.

Next, by thermally-curing the viscous admixture 50 which was pushed-in,the magnetic exterior body 20 which covers the coil assembly body 10 isformed (Forming Process S40).

As shown in FIG. 14, in the forming process S40 of the firstmanufacturing method, the magnetic exterior body 20 is formed bythermally-curing the viscous admixture 50 in the inside of the mold body60 (Process S41 a). In the process S41 a, the heating is executed untilthe thermal curing temperature or more with regard to the thermosettingresin (second component). In a case in which the solvent (thirdcomponent) is added to the viscous admixture 50, the solvent is removedby being vaporized in the process S41 a. Then, after the magneticexterior body 20 is thermally-cured sufficiently, the coil component 100is taken out from the mold body 60 (Process S42 a). The molded coilcomponent 100 is shown in FIG. 2C. Heat-resistant tray 74 will bementioned below.

When taking out the coil component 100 from the mold body 60, it ispreferable to use a take-out jig such as a protruding rod 34 (see FIG.6B) or the like. It is preferable to take out the coil component 100 ina state in which the integrated jig 61 and the bottom unit 64 areseparated and the cavity portion 62 is made to pass-through in the upand down direction. It is allowed to take out the coil component 100toward either of the upward and downward directions of the cavityportion 62.

It is allowed to carry out a post-treatment process after the formingprocess S40. For the post-treatment process, it is possible to cite apolishing process and/or a sealing process of the surface of themagnetic exterior body 20. It is allowed to form a coated-layer 80 ofthermosetting resin on the surface of the magnetic exterior body 20which is formed in the forming process S40. Thus, in the sealingprocess, it is possible to affix a seal on the coated-layer 80 byheating toward specified characters or graphic patterns. Thethermosetting resin of the coated-layer 80 is made to be the secondcomponent of the viscous admixture 50 and it is allowed to use the samekind of resin material as mentioned above or to use a different kindthereof.

In this manner above, the coil component 100 is produced by the firstmanufacturing method.

Next, there will be explained second to tenth manufacturing methods.Repetitive explanations with those in the already describedmanufacturing methods such as the first manufacturing method or the likewill be omitted arbitrarily. For example, the process S11 b in thepreparing process S10, the process S21 b and the process S22 b in theputting-in process S20 or the like of the second manufacturing methodare common to the process S11 a, the process S21 a and the process S22 ain the first manufacturing method respectively and therefore, only thereference numerals are indicated in the flowcharts of FIGS. 11 to 14 andthe explanations thereof will be omitted. It is assumed that thesituation is all the same also with regard to other manufacturingmethods.

<Second Manufacturing Method>

The second manufacturing method is carried out according to respectiveprocesses which are shown by being added with suffixes “b” in theflowcharts of FIGS. 11 to 14.

The second manufacturing method is common to the first manufacturingmethod except an aspect that in the pushing-in process S30 shown in FIG.13, the press body 30 is pressed against the swelling portion 52 whilebeing rotated in an in-plane direction of the opening portion 70. Morespecifically, while the press body 30 is descended substantially withoutrotation with respect to the swelling portion 52 (Process S31 a) in thefirst manufacturing method, in the second manufacturing method, thepress body 30 is pressed against the swelling portion 52 by beingdescended while being rotated axially (Process S31 b). In the secondmanufacturing method, as shown by broken lined arrows in FIG. 2A, thepress body 30 is descended as far as the upper surface of the mold body60 by an elevation mechanism (not shown) while being axially-rotatedcoaxially with the grasping portion 32.

Thus, according to the second manufacturing method, the swelling portion52 is pressed in a state in which the viscous admixture 50 is loadedwith shearing stress by the rotating press body 30 and the viscositythereof is lowered. For this reason, it is possible to heighten thefluidity of the viscous admixture 50 in the inside of the cavity portion62 compared with that in the first manufacturing method and it ispossible to further suppress a phenomenon in which an air gap is causedin the periphery of the coil assembly body 10.

<Third Manufacturing Method>

The third manufacturing method is carried out according to respectiveprocesses which are shown by being added with suffixes “c” in theflowcharts of FIGS. 11 to 14.

The third manufacturing method is different from the first manufacturingmethod in an aspect in which in the forming process S40 shown in FIG.14, complete-curing is carried out after taking out the coil component100 from the mold body 60. More specifically, in the first manufacturingmethod, the magnetic exterior body 20 is thermally-cured by heating themold body 60 up to the temperature by which the viscous admixture 50 iscompletely-cured (Process S41 a) and the coil component 100 after beingcured are taken out from the mold body 60 (Process S42 a). On the otherhand, in the third manufacturing method, the viscous admixture 50 isthermally-cured by a first temperature in the inside of the mold body 60(Process S41 c) and the semi-cured viscous admixture 50 is taken outtogether with the coil assembly body 10 from the mold body 60 (ProcessS42 c). Then, the taken-out viscous admixture 50 is thermally-cured(completely-cured) by a second temperature which is higher than thefirst temperature (Process S43 c). More specifically, in the thirdmanufacturing method, the coil component 100 is taken out from the moldbody 60 after semi-curing the viscous admixtures 50 by a comparativelylow temperature in the inside of the mold body 60 and the magneticexterior body 20 is completely-cured by a comparatively high temperatureon the outside of the mold body 60.

The first temperature is less than the thermal curing temperature of thethermosetting resin (second component). In case of including a solvent(third component) in the viscous admixture 50, the first temperature isset to be the volatilization temperature or more with regard to thesolvent. The second temperature is the thermal curing temperature ormore with regard to the thermosetting resin which is included in theviscous admixture 50. The solvent is vaporized and the viscous admixture50 becomes a semi-cured state by heating the mold body 60 and theviscous admixture 50 by the first temperature. It is allowed to set thefirst temperature as the curing-start temperature or more with regard tothe thermosetting resin and also allowed to set it as a temperature lessthan the complete-curing temperature.

In the third manufacturing method, by taking out the coil component 100from the mold body 60 in a state in which the viscous admixture 50 issemi-cured by a first temperature of comparatively low temperature,there can be obtained such a merit that the washing process of the moldbody 60 is easy. More specifically, as shown in FIG. 9A, a residue 73 ofthe viscous admixture 50 which was rubbed and cut in the pushing-inprocess S30 adheres to the periphery of the mold body 60. In order tomanufacture the coil components 100 continuously by using the mold body60 repeatedly, there is a case in which there is carried out a washingprocess for removing such a residue 73. At that time, if the residue 73is completely-cured, a lot of time is required for the washing process.On the other hand, by taking out the coil component 100 from the moldbody 60 in a state in which the viscous admixture 50 and the residue 73are semi-cured by heating the mold body 60 by the first temperature ofcomparatively low temperature such as in a case of the thirdmanufacturing method, it is possible to remove the residue 73 easilyfrom the mold body 60 after the take-out thereof.

With regard to the coil component 100 which is taken out from the moldbody 60 in the process S42 c, it is preferable to completely-cure themagnetic exterior body 20 thereof by being heated by the secondtemperature in a state of being placed on a heat-resistant tray 74 asshown in FIG. 2C.

<Fourth Manufacturing Method>

The fourth manufacturing method is carried out according to respectiveprocesses which are shown by being added with suffixes “d” in theflowcharts of FIGS. 11 to 14.

The fourth manufacturing method is a method obtained by combining thesecond and third manufacturing methods. Specifically, in the pushing-inprocess S30 shown in FIG. 13, similarly as the second manufacturingmethod, the press body 30 is pressed against the swelling portion 52while being rotated in an in-plane direction of the opening portion 70(Process S31 d). In addition, in the forming process S40 shown in FIG.14, the viscous admixture 50 is thermally-cured (semi-cured) by a firsttemperature in the inside of the mold body 60 (Process S41 d) and thesemi-cured viscous admixture 50 is taken out together with the coilassembly body 10 from the mold body 60 (Process S42 d). Then, thetaken-out viscous admixture 50 is thermally-cured (completely-cured) bya second temperature which is higher than the first temperature (ProcessS43 d).

According to the fourth manufacturing method, the swelling portion 52 ispressed in a state in which the viscous admixture 50 is loaded withshearing stress by the rotating press body 30 and the viscosity thereofis lowered (Process S31 d) and therefore, it is possible to excellentlyspread the viscous admixture 50 in the whole cavity portion 62 includingthe periphery of the coil assembly body 10. Therefore, when taking outthe coil component 100 in a semi-cured state from the mold body 60(Process S41 d), it is possible to suppress the shape deterioration ofthe magnetic exterior body 20 excellently.

<Fifth Manufacturing Method>

The fifth manufacturing method is carried out according to respectiveprocesses which are shown by being added with suffixes “e” in theflowcharts of FIGS. 11 to 14. FIG. 5A is an exploded perspective viewshowing a mold body 60 which is used in fifth and sixth manufacturingmethods. FIG. 5B is an exploded perspective view showing a modifiedexample of the mold body 60 which is used in the fifth and sixthmanufacturing methods.

The mold body 60 which is used in the fifth manufacturing method isdifferent from that of the first manufacturing method in an aspect thatthere are included a plurality of split-molds 68, 69 which will producecavity portions 62 when combined with each other.

As shown in FIG. 11 and FIG. 5A, in the preparing process S10 of thefifth manufacturing method, a split-jig 67 and the bottom unit 64 areprepared for the mold body 60. The split-jig 67 is a mold in which aplurality of cavity portions 62 having rectangular shapes are formed bypenetration-shapes by combining a pair of split-molds 68, 69 with eachother. In FIG. 5A, there is exemplified a split-jig 67 by which sixpieces of cavity portions 62 are formed, but there is particularly nolimitation caused by the number of the cavity portions 62 andarrangement thereof. The split-molds 68, 69 and the bottom unit 64 areassembled integrally by a holder (not shown).

Each of the split-molds 68, 69 shown in FIG. 5A includes elongated andrectangular-shaped cavity portions 62 obtained by cutting therectangular-shaped opening portions 70 by a straight line which passesthe centers of the counter sides thereof. Each of the split-molds 68, 69which are shown in FIG. 5B and which relate to a modified example of themold body 60 includes triangular-shaped cavity portions 62 obtained bycutting the rectangular-shaped opening portions 70 by a straight linewhich passes the counter vertexes thereof. The pair of concave portions66 which are formed on the bottom unit 64 is disposed corresponding tothe installation direction of the coil assembly body 10 which is put inthe cavity portion 62. In FIGS. 5A and 5B, there is shown an example inwhich the concave portions 66 are formed in parallel with the sides ofthe rectangular-shaped opening portions 70.

More specifically, it is possible for the split-jig 67 shown in FIGS. 5Aand 5B to separate the split-molds 68, 69 each other in the orthogonaldirection with respect to the penetration direction (up and downdirection) of the cavity portion 62.

In the forming process S40 of the fifth manufacturing method, byseparating the plurality of split-molds 68, 69 each other, thesplit-molds 68, 69 are removed from the viscous admixture 50 which ispushed in the pushing-in process S30 (Process S41 e). Then, the magneticexterior body 20 is formed by thermally-curing the viscous admixture 50from which the split-molds 68, 69 are removed (Process S42 e).

More specifically, in the fifth manufacturing method, it is possible toseparate the split-molds 68, 69 from the viscous admixture 50 toward theside directions without pushing off the viscous admixture 50, which waspushed in the pushing-in process S30, from the cavity portion 62 byusing a take-out jig such as the protruding rod 34 (see FIG. 6B) or thelike. For this reason, in the process S41 e, it is possible to take outthe viscous admixture 50 in a state of the uncured state easily from themold body 60.

From such a viewpoint that it is possible to take out the viscousadmixture 50 easily from the split-jig 67, it is preferable to producethe split-molds 68, 69 by a resin material such aspolytetrafluoroethylene (PTFE) or the like which has an excellentmold-releasable property.

It should be noted that instead of the fifth manufacturing method, it isallowed to take out the viscous admixture 50 from the split-jig 67 afterbeing semi-cured similarly as the processes from the process S41 c tothe process S43 c in the forming process S40 of the third manufacturingmethod. More specifically, it is also allowed to employ a procedure inwhich after the viscous admixture 50 (magnetic exterior body 20) issemi-cured in the inside of the mold body 60 by a first temperature, thesplit-molds 68, 69 are separated from the viscous admixture 50, the coilcomponent 100 is taken out from the mold body 60, and thereafter, themagnetic exterior body 20 is completely-cured by heating the coilcomponent 100 by a second temperature.

<Sixth Manufacturing Method>

The sixth manufacturing method is carried out according to respectiveprocesses which are shown by being added with suffixes “f” in theflowcharts of FIGS. 11 to 14.

In the forming process S40 of the sixth manufacturing method, theviscous admixture 50 is thermally-cured by being heated together withthe split-jig 67 (Process S41 f). At that time, by separating theplurality of split-molds 68, 69 mutually, it is possible to reducephenomena in which the thermally-cured magnetic exterior bodies 20 areattached to the split-jig 67 and it is possible to take out the coilcomponents 100 easily from the split-jig 67 (Process S42 f).

Also in a case in which, such as the sixth manufacturing method, themagnetic exterior body 20 is completely-cured by heating the viscousadmixture 50 up to the second temperature in the inside of the mold body60 (split-jig 67), it is possible to take out the coil component 100easily by separating the split-molds 68, 69 each other (Process S42 f).

It should be noted that for the pushing-in process S30 of the fifth andsixth manufacturing methods, it is explained, in FIG. 13 similarly as ina case of the first manufacturing method, that the press body 30 isdescended substantially without rotation with respect to the mold body60 (Process S31 e and Process S31 f), but the present invention is notlimited by this configuration. It is also allowed to descend the pressbody 30 while being rotated with respect to the mold body 60 such as theprocess S31 b and the process S32 b of the second manufacturing method.

<Seventh Manufacturing Method>

The seventh manufacturing method is carried out according to respectiveprocesses which are shown by being added with suffixes “g” in theflowcharts of FIGS. 11 to 14. FIGS. 6A to 6C are front elevational viewsschematically showing seventh and eighth manufacturing methods of thecoil component. In the same drawings, with regard to the hatchingshowing the cross-section of the coil assembly body 10, the illustrationthereof is omitted.

The seventh manufacturing method is different from the firstmanufacturing method in an aspect in which the viscous admixture 50which is put in the cavity portions 62 is covered by a lid member 40having an excellent mold-releasable property, and in the pushing-inprocess S30, the viscous admixture 50 is pushed-in by pressing the pressbody 30 against the lid member 40.

More specifically, in the pushing-in process S30 of the first to sixthmanufacturing methods, the swelling portion 52 of the viscous admixture50 is rubbed, cut and planarized by ascending the press body 30 whilebeing rotated axially in contact with the upper surface of the mold body60. On the other hand, in the seventh and eighth manufacturing methods,owing to the pressing force by the press body 30, the upper surface ofthe viscous admixture 50 is pushed-in flatly through the lid member 40.

In the preparing process S10 of the seventh manufacturing method, asshown in FIG. 11 and FIG. 6A, the mold body 60 and the lid member 40 areprepared. The lid member 40 of this exemplified embodiment is a moldreleasing sheet which prevents the press body 30 from being attacheddirectly to the viscous admixture 50, and also, which can be peeledeasily from the magnetic exterior body 20 after the thermal molding.

The lid member 40 is composed of a resin material having an excellentmold-releasable property and it is possible as one example to use afluororesin material such as polytetrafluoroethylene (PTFE) or the like.There is no limitation for the thickness of the lid member 40 inparticular and it is also allowed to employ a plate shape, a block shapeor the like other than a so-called sheet shape. The lid member 40 hasapproximately the same shape as that of the opening portion 70 and hassubstantially the same shape and size. Thus, it is possible to arrangethe lid member 40 in the inside of the opening portion 70 without a gap.

In the putting-in process S20 of the seventh manufacturing method, thecoil assembly body 10 is put in the cavity portion 62 and the terminalportions 16 are fitted with the concave portions 66 of the bottom unit64 (Process S21 g). Next, the viscous admixture 50, which is measured ina predetermined amount, is put-in as far as a position lower than theopening portion 70 (Process S22 g). Further, the lid member 40 havingapproximately the same shape as that of the opening portions 70 isprovided in the inside of the opening portion 70. Then, in thepushing-in process S30 as shown in FIG. 13 and FIG. 6A, the press body30 having a thinner diameter than that of the opening portion 70 ispressed against the lid members 40.

Thus, by forming the lid member 40 in approximately the same shape asthat of the opening portion 70, it never happens that the viscousadmixture 50 leaks out from the gap between the opening portion 70 andthe lid member 40. In addition, by using the press body 30 having athinner diameter than that of the opening portion 70, it is possible toprevent the magnetic powders of the viscous admixture 50 from biting inbetween the press body 30 and the mold body 60.

In more detail, the viscous admixture 50 which was put in the putting-inprocess S20 is planarized by a squeegee (not shown) or the like ifdesired and thereafter, in the pushing-in process S30, the lid member 40is placed on the surface of the viscous admixture 50 (Process S31 g).Next, by descending the press body 30 substantially without rotation,the lid member 40 is pressed downward (Process S32 g). Thus, the lidmember 40 is prevented from being deformed caused by the friction forcewith respect to the press body 30. For a similar reason, after pushingthe viscous admixture 50 in the mold body 60 sufficiently, the pressbody 30 is ascended without rotation (Process S33 g).

In the forming process S40 of the seventh manufacturing method, as shownin FIG. 14 and FIG. 6B, first, the viscous admixture 50 which is coveredby the lid member 40 and pushed in the mold body 60 is taken out fromthe mold body 60 together with the coil assembly body 10 (Process S41g). Specifically, the viscous admixture 50 and the coil assembly body 10are pushed down by a protruding rod 34 or the like from the upward sideof the mold body 60. Next, the magnetic exterior body 20 is formed bythermally-curing the taken-out viscous admixture 50 (Process S42 g).When thermally-curing the viscous admixture 50, it is preferable tocarry out the thermal-curing in a state in which the viscous admixture50 and the coil assembly body 10 are placed on a heat-resistant tray 74.Then, after the magnetic exterior body 20 is thermally-cured, heatremoval is carried out if desired and thereafter, the lid member 40 ispeeled off from the magnetic exterior body 20 (Process S43 g). It isallowed to form a peeling start portion (not shown) on the one side ofthe rectangular shaped lid member 40 such that it is possible to peeloff the lid member 40 from the magnetic exterior body 20 easily as shownby an arrow in FIG. 6C. It is possible to form the peeling start portionby notching one side of the lid member 40 a little bit or by folding theone side thereof.

The coil component 100, which is manufactured by the seventhmanufacturing method, has a specific feature in which for the countersurface 22 with respect to the terminal portions 16 within the magneticexterior body 20, the magnetic powders thereof are arranged smoothlycompared with those of the circumferential surfaces 24 adjacent to thiscounter surface 22 (see FIG. 6C). Thus, the counter surface 22 isexcellent in glossiness compared with the circumferential surfaces 24,and a fine view is presented and concurrently, the mechanicalcharacteristic thereof is excellent. Such a counter surface 22 tells astory that the pushing-in process S30 and the forming process S40 werecarried out in a state in which the upper surface of the viscousadmixture 50 was covered by the lid member 40. More specifically, withregard to such a coil component 100, the magnetic exterior body 20 isfilled in the periphery of the coil assembly body 10 without a gap, andthe component has a fine view, is excellent in the mechanicalcharacteristic and is excellent in the yield property. In other words,the coil component 100, in which the magnetic powders of the countersurface 22 with respect to the terminal portions 16 are arrangedsmoothly compared with those of the circumferential surfaces 24, isexcellent in productivity.

<Eighth Manufacturing Method>

The eighth manufacturing method is carried out according to respectiveprocesses which are shown by being added with suffixes “h” in theflowcharts of FIGS. 11 to 14.

The eighth manufacturing method is different in an aspect in which theviscous admixture 50 is taken out after being semi-cured in the insideof the mold body 60 similarly as the third manufacturing method insteadof taking out the coil component 100 from the mold body 60 in an uncuredstate of the viscous admixture 50 in the forming process S40 of theseventh manufacturing method (Process S41 g).

More specifically, in the forming process S40 of the eighthmanufacturing method, the viscous admixture 50 is thermally-cured by afirst temperature in the inside of the mold body 60 (Process S41 h) andthe semi-cured viscous admixture 50 is taken out from the mold body 60together with the coil assembly body 10 (Process S42 h). Then, thetaken-out viscous admixture 50 is thermally-cured by a secondtemperature which is higher than the first temperature (Process S43 h).

Then, in the eighth manufacturing method, differently from the thirdmanufacturing method, the lid member 40 having an excellentmold-releasable property is peeled off from the completely-curedmagnetic exterior body 20 (Process S44 h). Thus, similarly as theseventh manufacturing method, the counter surface 22 with respect to theterminal portions 16 within the magnetic exterior body 20 is formedsmoothly and minutely, and there can be formed the coil component 100which has a fine view and is excellent in the mechanical characteristic.

<Ninth Manufacturing Method>

The ninth manufacturing method is carried out according to respectiveprocesses which are shown by being added with suffixes “i” in theflowcharts of FIGS. 11 to 14. FIGS. 7A to 7C are front elevational viewsschematically showing the ninth manufacturing method of the coilcomponent. In the same drawings, with regard to the hatching showing thecross-section of the coil assembly body 10, the illustration thereof isomitted.

The mold body 60 which is used for the ninth manufacturing method isformed by a resin material having an excellent mold-releasable property.For such a resin material, it is possible to cite a silicone rubbermaterial as an example. In the preparing process S10 of the ninthmanufacturing method shown in FIG. 11, there is prepared such a moldbody 60 (Process S11 i).

With regard to the mold body 60 which is used for the ninthmanufacturing method, as shown in FIG. 7A, the integrated jig 61 and thebottom unit 64 are formed integrally. At the bottom unit 64, there areformed the concave portions 66 for fitting the terminal portions 16thereto.

The mold body 60 which is used for the ninth manufacturing method hasflexibility and also, includes an aligned plurality of cavity portions62. In the putting-in process S20 shown in FIG. 7A and FIG. 12, theviscous admixture 50 and the coil assembly body 10 are put in each ofthe plurality of cavity portions 62. Specifically, the coil assemblybody 10 is put in the cavity portion 62 and the terminal portions 16 arefitted with the concave portions 66 (Process S21 i) and next, theviscous admixture 50 is put in the cavity portions 62 and the swellingportion 52 which overflows from the opening portions 70 is formed(Process S22 i).

In the pushing-in process S30, as shown in FIG. 7B, the swelling portion52 is pressed by descending the press body 30 while being rotated(Process S31 i) and further, the press body 30 is ascended, whilerubbing and cutting the swelling portion 52 by the press body 30(Process S32 i). Thus, the upper surface of the viscous admixture 50 isformed flatly with a height which is flush with the opening portion 70of mold body 60. It should be noted that it is also allowed in the ninthmanufacturing method to descend the press body 30 substantially withoutrotation similarly as the first manufacturing method.

In the forming process S40, by thermally-curing the respective viscousadmixtures 50 in the inside of the mold body 60, a plurality of magneticexterior bodies 20 are formed (Process S41 i). The ninth manufacturingmethod is different from the first to fourth manufacturing methods in anaspect in which as shown in FIG. 7C, the formed plurality of themagnetic exterior bodies 20 are taken out from the cavity portions 62 bybending the mold body 60 so as to bend backward in the alignmentdirection of the cavity portions 62.

More specifically, the mold body 60 which is used for the ninthmanufacturing method is formed by a resin material having flexibilityand also having excellent mold-releasable property, so that by bendingthe opening portions 70 of the mold body 60 as a whole so as to push andexpand them, the downward side of the integrated jig 61 is made to benarrower and the magnetic exterior bodies 20 are pushed out from thecavity portions 62. The mold body 60 is composed of a sufficiently softmaterial compared with those of the magnetic exterior bodies 20 andtherefore, it never happens that the mold body 60 damages the magneticexterior bodies 20 when taking-out the magnetic exterior bodies 20.According to the ninth manufacturing method, it is possible to take outa lot of coil components 100 after the forming speedily from the moldbody 60.

<Tenth Manufacturing Method>

The tenth manufacturing method is carried out according to respectiveprocesses which are shown by being added with suffixes “j” in theflowcharts of FIGS. 11 to 14. FIGS. 8A to 8C are front elevational viewsschematically showing the tenth manufacturing method. In the samedrawings, with regard to the hatching showing the cross-section of thecoil assembly body 10, the illustration thereof is omitted.

The tenth manufacturing method is different from the ninth manufacturingmethod in an aspect of the timing and the putting-in direction forputting the coil assembly bodies 10 with respect to the cavity portions62. In the tenth manufacturing method, it is possible to use the moldbody 60 which is used in the ninth manufacturing method.

As described above, the coil assembly body 10 is connected to the coil15 and is provided with the terminal portions 16 which are exposed fromthe magnetic core 12. After the viscous admixture 50 is put in thecavity portion 62 (Process S21 j) in the putting-in process S20 shown inFIG. 12, the coil assembly body 10 is put in the viscous admixture 50(Process S22 j). Specifically, the coil assembly body 10 is placed onthe viscous admixture 50 such that the terminal portions 16 are to bedisposed from the viscous admixture 50. Then, in the pushing-in processS30 shown in FIG. 13, the coil assembly body 10 which is placed on theviscous admixture 50 is pressed toward the viscous admixture 50 in thepushed-in direction.

In more specifically, in the process S21 j, a measured predeterminedamount of the viscous admixture 50 is put in the cavity portion 62 asshown in FIG. 8A. Next, in the process S22 j, the coil assembly body 10is placed on the viscous admixture 50 by directing the plate-shapedportion 13 thereof toward the upward direction. Thus, the core portion14 and the coil 15 which are portions of the coil assembly body 10 areburied-in with respect to the viscous admixture 50.

In the pushing-in process S30 shown in FIG. 8B, the coil assembly body10 is pushed-in more deeply with respect to the viscous admixture 50 bydescending the press body 30 without rotation (Process S31 j). At thattime, it is allowed to cover the upper surface of the plate-shapedportion 13 and the terminal portion 16 by a protection sheet 42 suchthat the press body 30 will not damage the plate-shaped portion 13 andthe terminal portion 16. By pushing down the press body 30 as far as apredetermined depth, the coil assembly body 10 is buried in the viscousadmixture 50 more deeply and the whole coil assembly body 10 except theterminal portions 16 is buried in the viscous admixture 50. From such astate, the press body 30 is ascended and the pushing-in process S30 isfinished (Process S32 j).

In the forming process S40 of the tenth manufacturing method, theviscous admixture 50 is thermally-cured by heating the mold body 60 andthe viscous admixture 50 (Process S41 j) and thereafter, thethermally-cured magnetic exterior body 20 (coil component 100) is takenout from the mold body 60 (Process S42 j).

As described above, the mold body 60 used in the tenth manufacturingmethod is formed by a resin material having flexibility and alsoexcellent mold-releasability. Thus, in the tenth manufacturing method,it is possible, as shown in FIG. 8C, to take out the formed plurality ofthe magnetic exterior bodies 20 from the cavity portions 62 by bendingthe mold body 60 so as to bend backward in the alignment direction ofthe cavity portions 62. Thus, it is possible to take out the pluralityof the coil components 100 from the mold body 60 easily and alsospeedily.

As described above, according to the first to tenth manufacturingmethods, the viscous admixture 50, which is put in the cavity portion 62in the putting-in process S20, is pushed in the pushing-in process S30,so that the viscous admixture 50 is filled in the inside of the cavityportion 62 preferably without causing an air gap in the periphery or thelike of the coil assembly body 10. Then, there are the above-mentionedunique features in the first to tenth manufacturing methods and thus, itis possible to produce the coil components 100 by high quality and byhigh productivity.

It should be noted that the present invention is not to be limited bythe exemplified embodiments mentioned above and includes embodimentssuch as various kinds of modifications, improvements or the like so longas the objects of the present invention can be achieved.

Having described preferred embodiments of the invention with referenceto the accompanying drawings, it is to be understood that the inventionis not limited to those precise embodiments and that various changes andmodifications could be effected therein by one skilled in the artwithout departing from the spirit or scope of the invention as definedin the appended claims.

What is claimed is:
 1. A manufacturing method of a coil componentcomprising: preparing a coil assembly body in which a coil is attachedon a magnetic core and a mold body which is formed with a cavity portionin the inside thereof and which includes at least one opening portion,putting a viscous admixture including magnetic powders and thermosettingresin and the coil assembly body in the cavity portion, pushing theput-in viscous admixture in the mold body, and thermally-curing thepushed-in viscous admixture and forming a magnetic exterior body whichcovers the coil assembly body, wherein the viscous admixture put in thecavity portion is covered by a lid member, in the pushing, the viscousadmixture is pushed in by pressing a press body against the lid member,after the pushing, the coil assembly body with the viscous admixturecovered by the lid member is taken out from the mold body, in thethermally-curing the pushed-in viscous admixture, the magnetic exteriorbody covered by the lid member is formed by thermally-curing thetaken-out viscous admixture, and after the thermally-curing thepushed-in viscous admixture, the lid member is peeled away from themagnetic exterior body.
 2. The manufacturing method of a coil componentaccording to claim 1, wherein in the putting, the viscous admixture isput as far as a lower position compared with the opening portion, thereis provided the lid member having approximately the same shape as theopening portion inside the opening portion, and in the pushing, thepress body having a thin diameter compared with the opening portion ispressed against the lid member.
 3. The manufacturing method of a coilcomponent according to claim 1, wherein the mold body is formed by aresin material having an excellent mold-releasable property.
 4. Themanufacturing method of a coil component according to claim 1, whereinthe mold body includes a plurality of split-molds which define thecavity portions by being mutually combined.
 5. The manufacturing methodof a coil component according to claim 4, wherein the split-molds areremoved from the viscous admixture which was pushed-in the pushing bymutually separating the plurality of split-molds and the magneticexterior body is formed by thermally-curing the viscous admixture fromwhich the split-molds were removed.
 6. The manufacturing method of acoil component according to claim 1, wherein in the putting, the coilassembly body is attached to the bottom portion of the cavity portionand thereafter, the coil assembly body is buried by putting the viscousadmixture, and in the pushing, the viscous admixture facing the openingportion is pressed toward the coil assembly body.
 7. The manufacturingmethod of a coil component according to claim 6, wherein the coilassembly body includes a terminal portion which is connected to the coiland which is exposed from the magnetic core, and at the bottom portionof the cavity portion, there is provided a concave portion which housesthe terminal portion and which separates the terminal portion and theviscous admixture.
 8. The manufacturing method of a coil componentaccording to claim 1, wherein the coil assembly body includes a terminalportion which is connected to the coil and which is exposed from themagnetic core, in the putting, the viscous admixture is put in thecavity portion and thereafter, the coil assembly body is placed on theviscous admixture such that the terminal portion is exposed from theviscous admixture, and in the pushing, the placed coil assembly body ispressed toward the viscous admixture in the pushing-in direction.
 9. Themanufacturing method of a coil component according to claim 1, wherein athermosetting-resin coated-layer is formed on the surface of the formedmagnetic exterior body.